In most of the use cases discussed in this proposal, the preferences that are shared are used to customize a user's experience on the websites they visit. However, it is also possible that a browser manufacturer might modify the browser codebase to also lookup a user's browser preferences from their PDS, such as their default search provider. For example:
Tom uses yahoo.com as his PDS, and has configured his default search provider to be yahoo.com
Tom buys a new laptop, and logs into yahoo.com.
Yahoo detects that his CDS setting is empty, so it prompts him to set yahoo.com as his PDS through the CDS domain
The browser on Tom's computer detects that the CDS cookie has changed, and automatically looks up his PDS preferences, and looks for any browser preferences
It finds that Tom uses yahoo.com as his default search provider, so the browser automatically changes its built-in search box to use yahoo.com